Filling modes of polymer during submicron and nano-fabrication near glass transition temperature

In this study, we used a glass mold coated with TiN layer to fabricate submicron and nano-gratings on a PMMA (polymethylmethacrylate) film. The cavities on the mold, with sizes varying from 71 nm to 980 nm, was etched by ion beam. The deformation and filling modes of polymer during fabrication process were studied. Dual-peak deformations, which were considered as the characteristic filling modes of “viscous-dominant” polymer, were observed. Because our fabrication experiments were conducted near the glass transition temperature (Tg) of PMMA at which the polymer was “elastic–plastic-dominant”, the appearance of the dual-peak filling mode meant solid-state polymer might exhibit some characters of fluidic polymer at submicron and nano-scale. In addition, we presented a simple and effective mold release process at the end of this paper, which could reduce defects during molding release process.